Religion: The Holy Ghost

Theologians through the ages have bent their brains on the nature and
function of God the Father and God the Son. But the third person of the
Christian Trinity has received relatively scant theological
consideration. "With a few inconsequential exceptions," writes
President Henry P. Van Dusen of Manhattan's Union Theological Seminary,
"there has been hardly a period in the church's history, hardly a
school of Christian theology, hardly an individual theologian who has
given to the Holy Spirit the attention . . . merited."